18-electron rule
Organometallic Compounds · Chemistry
Study notes
Does Fe(CO)₅ obey the 18-electron rule? Count. Step 1: Fe(0): group 8 → 8 valence electrons. Step 2: Each CO donates 2 e⁻: 5 × 2 = 10. Step 3: Total = 8 + 10 = 18 ✓. Step 4: Stable! (Ionic method: Fe(0), CO neutral — same result.)